Coadsorption of lithium and oxygen on W(1 1 2): Nanosized facets versus single crystals

Coadsorption of lithium and oxygen on a nanosized W-tip is studied using field ion appearance energy spectroscopy (FIAES). Binding energies of coadsorbed Li-adatoms are derived locally for chosen atomic sites on (1 1 2) facets for different oxygen and Li-coverages. Independently, the binding energies of Li-adatoms in coadsorbed Li/oxygen layers are determined for macroscopic W(1 1 2) single crystal samples from the adsorption isobars in adsorption–desorption equilibrium experiments and compared with the local nm-scale measurements. The comparison reveals a very good agreement of results obtained by two different methods on differing length scales.

Research highlights
► Binding energies of coadsorbed Li-adatoms were obtained using field ion appearance energy spectroscopy (FIAES).
► The FIAES measurements were performed for chosen atomic sites on W(1 1 2) nanofacets.
► Different Li and oxygen coverages within the Li-O coadsorption layers were studied.
► Independently, the binding energies of coadsorbed Li-adatoms were obtained for a W(1 1 2) single crystal surface.
► For the single crystal studies adsorption-desorption equilibrium experiments were performed.
► The data obtained on a nm-scale are compared with results of the single crystal studies.